Improvement in instruments por laying out stair-bailings



@einen taies gatrnt @ffice ALEXANDER GLOW, OF ERIE, PENNSYLVANIA, ASSINOR TO HIMSELF AND JOHN HENDRY, OF THE SAME PLACE.

Letters Patent No. 66,796, dated July 16, 1867.

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TO ALL WI-IOM IT MAY CONCERN: l

Be it known that I, ALEXANDER GLOW, of the city and county of Erie, in the State of Pennsylvania, lhave invented a ne and improved Instrument for Laying out Stair-Railing; and I do hereby declare that the following is a full and exact description thereof, reference being had to the accompanying drawings, making part of this specification, iu which- Figure 1 is a side elevation.

Figure 2, a vertical or plan view, anc

Figure 3, a plan view of the same apparatus, having the tracing-arm removed and the trammel M applied, to adapt it to describing elliptical stair-railings.

Like letters indicate corresponding parts in all of the figures.

My invention is intended to furnish an accurate guide for laying out the hand-rail of circular and elliptical' stair-cases; and consists, first, of a vertical standard or rod A, fixed in a suitable vbase-support, B, on which the horizontal tracing-amm C is hung, so as to be capable of moving up and down, and revolving around its centre at will; second, at a convenient distance from the foot o f this standard a block or cleat, D, provided with a groove to receive'the triangular pattern E, is atiixed to the base. This pattern is formed of an angle which correctly represents the rise or inclination of thestair-case, its lower edge being of the same length as the tread of one of the steps, and placed horizontally, and its vertical side of a height equal to that of the rise of the step,

p which givesthe inclined ,sido the same angle or pitch as the stairs. The plank from which the hand-rail is to be worked is laid on the pattern, its lower side parallel with and resting on the inclined edge a, and its upper supported by a cross-bar, F, on the standard F. The latter is made adjustable vertically by a series of holes e e and keyf, to sustain it at a height to support the upper end of the plank at the inclination-required to correspond to the edge of the pattern, and is also adjustable by revolving horizontally. A pivoted cleat, G, is also provided to hold the foot of the plank ini-'the proper position. This is also adjustable by swinging on its centre, being held by the pivot-pin L and movable pin z', fitting in the holes jj. The arm C is provided with'a sliding-head or holder, H, carrying a pencil, g, or other marking instrument, which should always be adjusted to work perpendicularly. This pencil being adjusted, by moving it from the standard A to a distance equal to th'c radius of the well of the stair, is moved upon the surface of the inclined plank K from the bottom upward, the arm revolving on the post A and rising on it with the inclination of the plank as it moves, being jointed sufficiently loose for this purpose. The mark thus traced on the pla'nk describes the exact line and curve of the finished rail, the standard A representing the centre of the well-hole ofthe stair. One line being. traced, the head II is moved a distance equal to the width designed for the rail, and another line is traced, which, being parallel, corresponds exactly with the rst. 'lhese lines furnish a reliable guide forthe joiner to follow in sawing out the rail before finishing, and/ save a great amount of labor and calculation, besides having the advantage of being entirely correct. The arm C may be dropped below the plank, and the pencil-holder reversed to bring the point above it in an upright position, when lines may be traced on the under side correspending with those on the upper` side of the plank. l

It will be apparent thatl the pattern E must for every stair-case be made with its edge a of the exact inclination of the rise of the step, when, if the plank be held in contact with it, no error can occur in the laying 0111i 0f the I'RL The C1'0SSbIl1 F' iS pl'OVdeflwith adjustable heads ZZ, by means ot' which the plank may be clamped and held firmly to its place. Y

For laying out elliptical stair-rails, I remove the arm C from the standard, and place upon the latter a tube or sleeve (o, iig. 3) fitting snugly, but turning upon it. This tube is squared on its outside, and receives the trammel M, which slides up and down upon it. The sleeve tits in a square socket of the base to hold it from turning on the standard except as required when it is raised ou't of the socket for the purpose. N -is the beam of the trammel, with its two bearings r r, which slide in the groove a, andp is the pencil or marker, vertically suspended from the beam. The plank K being fixed to the inclination of the pattern E, and the bearings r r and pencilp set tothe size and proportion of the ellipse, the-beam is moved around in the same mannerI as the arm before described, "correctly tracing the curve and twist of the rail.

This simple apparatus can be used by any joiner, and being a certain guide, eieets a. great saving of time and labor in the difficult Work of describing rails for curved, elliptical, and spiral stairs.

What I claim as my invention, and desire to secure by Letters Patent, ils- The herein-described apparatus, consisting of the standard A, tracing-arm C, pattern E, adjutable .support F, and foot-clamp Gr, arranged and operating substantially as and for the pur-poses herein set forth.

I also claim the combination of a, traumiel with the above-claimed apparatus, arranged and operatingsu stantinlly as and .for the purposes set forth.

In Witness whereof I have hereunto signed my name 1n the presence of two subscribing witnesses.

ALEXANDER- GLOW.

Witnesses:

J oHN Grrmmixfi,Y JOHN HENDRY. 

